Vacuum pump



July 31, 1928. 1,679,132

F. D. HOLDSWORTH VACUUM PUMP Filed Oct. 19, 1921 Patented July 31, 1928.

UNITED .STA-,TES

ltr/falaz PATENT ioFFlce- FRED D. HOLDSWORTH, OF CLAREMONT, NEW HAMPSHIRE, k.ASSIGNOR TO SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS.

VACUUM PUMP.

Application led October 19,1921. Serial No. 508,858.

My invention relates to vacuum pumps.

It has 'for its object to provide an improved' vacuum pump. A further object of my invention is to provide an improved cooling means iior sucha pump wherein a constant circulation ot cooling medium is maintained about the cylinder and all trap` ping of air or the like is eliminated. These and other-advantages of my improved construct-ion will, however, hereinafter be more fully brought out.

In the accompanying` drawings I have shown for purposes ot illustration one einbodiment which my invention may assume 3 in practice. Y a

In these drawings,-

Fig. 1 is a central longitudinal partial sectional view of a pump cylinder constructed in accordance with this form of my inven- 3" tion. Y

Fig. 2 is a sectional view on line 2 2 oi Fig. 1. 1

Fig. 3 is a sectional viewv on line 3 3 ot' Fig. 2. f j Y 4 is a detail view showing the air escapepassage.

In this illustrative construction I have shown a cylinder 1 having a pistou 2 movable therein, the piston beineadapted to be ne reciprocated in the cylinder in a well known manner to draw an air or gas from a usual intake. 3 through passages 4f and radially located valves 5 and to discharge the air or `gas through radially located valves 6, pas- I' sages 7 and an outlet 8.

In my improved construction it will be noted that the piston is provided with beveled edges 9 on its opposite sides and that the cylinder is provided with correspondingly shaped ends 10 while the valves 5 and 6 are disposed at an angle in heads 11 and 12 suitably connected to a central cylinder carrying member 13 in such a manner that the ends of the valves lie substantially in the plane of the beveled surfaces 10 of the cylinder. y

Attention is also directed to the fact that the cylinder 1 is surrounded by a suitable cooling jacket 14.- receiving a cooling medium from a suitable inlet pipe 15 at its bottom. From this inlet 15 the cooling medium passes up and around'each side ofthe lower half of the cylinder, the member-16 shown in Figs. 1 and 2 being only a boss, until it reaches enlarged chambers 17 which in turn communicatev through ports 18 Withlateral extensions on the opposite sides of cooling chambers 19 and 2() in the cylinder heads, the chamber 2() herein extending around the pis? ton rod. lVhen the cooling medium enters these chambers 19, 20, of which o-ne is shown in Fig. 2, it will evidently lill the sameup to the points 21 and since these points are loW- er than the end walls of the chambers, the cooling medium will pass out of ports.22, 23, into and around the upper half oli-the jacket 14 to an outlet or discharge pipe 24 at the top thereof, it being understood that the member 25 is a' cylinder lubricating stud in no way interrupting the flow of the cooling medium and acting` only to enable lubricant to be supplied-from a suitable pipe 26 to asuitable passage 27 in the stud leading to the cylinder.

Vit-h the cooling medium in the chambers 19 and 2O and Vfilling the. same up' to the points 21, air will evidently be trapped in the upper parts oi the chambers and thereby produce adead space incapable ofV being cooled by the cooling system, unless some air outlet is supplied. To eliminate this difficulty, I have'provided anoutlet in the form of a passage 28 leading upward from the top of each of-these chambers 19 and 20 into the upper half ofv the packet 14 so that any air trapped in the chambers 19 and 2O may escape into the cooling medium i in the upper halfv of the jacket and with that cooling medium pass out` through the discharge 24the passage 28 thereafter acting as a part of the circulating system.

es a result of my improvement, it will be observed that ythrough mv irrmvovedy arrangement ot piston, cylinder, and valves, clearance is minimized while through the use of the cooperating cooling' means,l all portions of the walls ot the cylinder save those carrying the valves are eii'e'ctualllv cooled bv a constant circulation of the coolling medium, while any vair which' would otherwise be trapped in the hea-ds is caused to pass out into the circulating stream and thereby permit circulation throughall parts ot the coo-ling system. While I have in this application specifically described one form which my invention. may assume in practice, it willbe understood that this form of the/same is shown for purposes of illustration and that the iu vention may be modified andfembodied in vaabl CII

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a plural chambered jacket surrounding said cylinder, coaxial chambers in the heads of said cylinder, and means for establishing a llow ci' cooling medium through said jacket and chambers including connections between vone part otsaid jacket and said chambers and from said chainbers 'to the other part oit said jacket, and a branch passage leading from said chambers into one oit the parts ot said jacket.

2. In a pump, fa cylinder, a piston therein., a plural chambered jacket surrounding said cylinder, coaxial chambers in the heads of said cylinder, andmeans 'for establishing a flow of cooling medium through said jacket and chambers including oppositely disposed. discharge and inlet ports at the adjacent ends of the parts oit said jacketl and communicating with said chambers, and branch passages one leading from each ot said chambers into the upper part of said jacket.

3. Ina pump, a cylinder, a piston therein, a plural chambe-red jacket surrounding said cylinder, coaxial chambers in the heads oil said cylinder, and means tor establishing a flow of cooling medium through said jacket and chambers including oppositely disposed discharge and inlet ports at the adjacent ends et the parts ot said jacket communi.- cating Awith said chambers, and branch pas sages one disposed in the upper part of each of said chambers and communicating with the discharge.

4. In a pump, a cylinder, an upper and lower jacket surrounding said cylinder, chambers in the heads of said cylinder, and passages connecting both o'l said jackets with said chambers, said passages connecting the lower jacket with said chamber. being adapted to prevent the trapping oit air in said lower jacket.

5. In a pump, afcylinder, an upper and lower jacket surrounding said cylinder and eachV extending substantially the entire length o'l the latter and including a trans verse partition separating the same, chambers in the heads of said cylinders, and transverse passages disposed adjacent said partition to connect said lower jacket with said chambers.

6. Ina pump, a cylinder, an upper and Vlower jacket surrounding said cylinder, coaXially disposed chambers in the heads oi said cylinder, said chambers being of reduced diameter from said jacket, and transverse passageways connecting said jackets with said chambers.

7. In a pump, a cylinder, an upper and lower jacket surrounding said cylinder including a partition separating the same, c0- axially disposed chambers in the heads of said cylinder, said chambers being of reduced diameter from said jacket, and trans verse passageways connecting said jackets with said chambers, said passageways terminating at one end in said jackets adjacent said partition.

8. In a pump, a cylinder, separated jackets surrounding the same, a chamber in the head of said cylinder of smaller diameter than said jackets, and a transverse passage connecting said chamber and jackets.

9. In a pump, a cylinder, separated jackets surrounding the same, a chamber in the head of said cylinder of smaller diameter than said jackets, and a transverse passage connecting said chamber and jackets, said passage being disposed below the level which liquid within said chamber and jacket willV normally assume.

l0. In a pump, a cylinder, aA jacket surrounding the same, a chamber in the head of said cylinder of smaller diameter' than said jacket, a transverse passa-ge connecting said chamber and jacket, said passage being disposed below the level which liquid within said chamber and jacket will normally assume, and a second passage disposed above the hrst mentioned passage and connecting the upper portion of said chamber with said jacket, and constituting means for prevent.

ing the trapping of air in said'chamber.

ll. In a pump, a cylinder, a plural chambered cooling jacket surrounding the same, a cooling chamber in the head ol' -said cylinder and whose diameter is less than that of the cylinder jacket, and a transverse passage adapted to allow communication between the adjacent portions ot the plural chambers and the chamber in said head.

l2. In a pump, a cylinder, a piston reciprocable therein, a water jacket surrounding said cylinder, water chambers in the head-s of said cylinder, means for connecting said jacket and chambers, and branch passages connecting said jacket and chambers.

13. In a pump', a cylinder having heads, and jacket means including a plural chambered jacket surrounding said cylinder, chambers one in each cylinder head, and means for establishing a llow ot' temperature controlling medium to fill completely said jacket and chambers in said heads including means providing communication between the chambers of said cylinder jacket and said chambers in the heads arranged at opposite sides of said cylinder and at opposite ends thereof, and means for preventing the trapping of air in said several chambers in cluding branch passages connecting said chambers in said heads with said jacket 'lor the cylinder.

In testimony whereof I afX my signature.

FRED D. HoLDsWonrH. 

